ABSTRACT Hematopoietic cell transplantation (HCT) can cure many patients, but often with the risk of late effects and significantly impaired quality of life (QOL). Whilst tools are available to assist patients and clinicians in predicting individualized outcomes early post-HCT (such as the Center for International Blood and Marrow Research (CIBMTR) 1-year survival calculator), these are currently almost exclusively based on clinical and demographic factors, and predict survival, but not QOL. Despite recent studies showing that pre-HCT patient- reported outcome (PRO)s are significantly predictive of both survival and QOL, few transplant centers routinely collect these. Compelling reasons for the lack of systematic PRO collection include lack of agreement on the most accurate measure, skepticism that PROs offer novel information over clinician judgment, and uncertainty regarding how to integrate them with current HCT tools. The goal of this study is to address these deficits by identifying a short set of discriminating PRO questions, from existing PRO measures, and to incorporate these into tools to predict individualized survival and long term QOL. Our 3 specific aims are: 1) determine the shortest set of pre-transplant PRO elements which will maintain a significant association with survival post- transplant and use this to enhance and extend the existing CIBMTR 1-year survival calculator, 2) develop a new set of calculators which predict 1-year post-HCT QOL, and 3) predict long-term QOL by incorporating both pre-and post-HCT PROs and other post-HCT complications. We will pursue these aims by leveraging the unique PRO data which has been collected on prospective clinical studies performed by the NHLBI-funded CIBMTR and the affiliated Blood and Marrow Transplant Clinical Trials Network (BMT CTN). These organizations strongly encourage secondary analyses and have defined mechanisms by which to achieve this. We will include seven studies which collected PRO data using either the FACT-BMT, SF36 or both. The total sample is 3236, a very large number of patients when considering this rare intervention. This cohort captures a broad representation of adult patients over a 15-year period. In addition to PRO data each study has comprehensive and consistently collected clinical data, including pre-HCT patient and disease variables, transplant characteristics and post-HCT outcomes. Every study includes baseline PRO data (pre-HCT), and PROs collected at multiple post-HCT time points (up to five years). The results from our investigation will have an immediate and significant impact on patients undergoing HCT by enhancing and standardizing HCT tools for individual patient prognostication, both for survival and QOL post-HCT.